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Sökning: FÖRF:(Carina Gunnarsson)

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  • Gunnarsson, Carina, et al. (författare)
  • Sustainable straw potential in sweden – a case study to supply straw for ethanol production
  • 2020
  • Ingår i: European Biomass Conference and Exhibition Proceedings2020, Pages 86-8828th European Biomass Conference and Exhibition, e-EUBCE 2020; Virtual, Online; ; 6 July 2020 through 9 July 2020. - : ETA-Florence Renewable Energies. ; , s. 86-88
  • Konferensbidrag (refereegranskat)abstract
    • When agriculture is to supply a growing bioeconomy with biomass, straw has been identified as one of residues with the largest potential. As removal of straw from fields will have a negative impact on soil humus development compared with straw incorporation it is important to make sure that a system including straw removal does not negatively effect the long-term soil fertility. As part of the EU-financed project AGROinLOG a Swedish demonstration case was made to supply 80,000 tonnes of winter wheat straw annually to 2nd generation bioethanol production. The straw removal from the case study area of Norrköping and surrounding counties, in the south-eastern part of Sweden, was evaluated from a soil fertility aspect using a model that estimates the sustainability of a cropping system regarding soil fertility and yield levels based on humus content, climate and soil type. The assessment revealed the possibility to remove 230,000 tonnes of winter wheat straw from the surrounding counties of Norrköping without reaching the humus limit. The margin to 80,000 tonnes is large and collecting this amount of winter wheat straw annually may well be possible. 
  • Gunnarsson, Carina, et al. (författare)
  • Vall till etanolproduktion - koncept för vall i växtföljden
  • 2020
  • Rapport (övrigt vetenskapligt)abstract
    • This report is about ley for ethanol production, with focus on the cultivation and handling, and is part of the project " Biofuel from agricultural side streams and straw in a system perspective " financed by the Swedish Energy Agency. The project is a continuation of the issue of secure raw material supply from the EU project AGROinLOG, which is about producing ethanol from straw.In order to be cost effective, ethanol is usually produced in large-scale plants, and with straw as a feedstock a secure supply of large quantities of straw is required. Producing ethanol from ley broadens the raw material base and is an opportunity to secure the supply of raw materials, especially during years with low cereal yields or with difficult harvest conditions for the straw. Introducing ley to a cereal-dominated crop rotation gives many positive effects on the cultivation system and to subsequent crops. There need to be a market and a buyer of the crop for the grain producers to be interested in ley cultivation. This report focuses on how a concept for ley to ethanol could look from the farmer's perspective.One question in the project was if the choice of grass and legumes variety is important. Four varieties of grass, as well as red clover and alfalfa, were harvested and collected in the project, in pure stand from Lantmännen's variety trials in Lännäs and Svalöv. The interviews with farmers conducted in the project showed that nitrogen fixating legumes such as clover and alfalfa are interesting from a farmer’s perspective for the positive effects, they have on the cultivation system. They should preferably be cultivated in combination with a fast-growing grass variety. The analyses that were done to investigate how the different ley species work as substrates for ethanol and bio-oil production showed that all the tested varieties work in these processes.In order to supply an ethanol plant with substrate all year round, the possibility to deliver both fresh and ensiled grass was studied. Fresh ley can be supplied to the plant from late May to late October. Depending on the extent of the fresh ley supply, it is complemented with silage or straw to cover the daily feedstock need.In order to avoid losses and heating of the material before entering the plant, the fresh ley should be harvested continuously every or every second day. Also, the ley should be physically damaged or cut as little as possible during harvesting and handling. The harvesting of fresh grass can be done in two steps. First the grass is mowed and left in swaths on the field. After that a forage wagon picks up the ley followed by transport to the plant. The other option is a direct-harvesting system using a tractor with a direct cut forage wagon and a mower in the front. The grass is cut and directly put in the wagon for transport to the plant. Which system to choose depends on how much grass is to be delivered per occasion and what degree of damage to the structure that is desired before delivery. For the ensiled ley the same kind of large-scale, cost-effective harvesting system usually used for harvesting of ley for animal production is suggested, typically consisting of a mower followed by a self -propelled precision chopper with separate wagons for transport to the plant.Essentially, three actors are involved in the delivery of ley to the ethanol plant, the farmer, the ethanol producer and a contractor who performs one or more steps in the harvesting and handling chain. Depending on the interests and conditions of the actors, two alternatives can be used to describe who is doing what. In option 1, the farmer establishes the ley and sells it on root. Then it is the buyer, or a contractor hired by the buyer, who handles harvesting, transport and storage. Depending on conditions on farm and plant, storage can be done on farm, on an intermediate storage or on plant. Option 2 means that the farmer has a more active role in cultivation, harvesting and transport and delivers the ley to the plant, either fresh at harvest or ensiled during the rest of the year.Two alternative concepts have been identified for delivering ley to ethanol production, where the proximity to the ethanol plant is what distinguishes the concepts. The concept "close" is aimed at farms located a short distance from Agroetanol. Fresh ley grass can be delivered with tractor to the plant during the growing season and ensiled ley grass is delivered by truck from the farm. The short distance makes it more interesting to receive, primarily, liquid residual streams that are produced at the ethanol plant. For the farm "further away" it is primarily silage that can be delivered because the silage has a lower water content compared to fresh ley, which means that it has lower transport costs.
  • Suardi, Allessandro, et al. (författare)
  • Admixing chaff with straw increased the residues collected without compromising machinery efficiencies
  • 2020
  • Ingår i: Energies. - : MDPI AG. - 1996-1073 .- 1996-1073. ; 13:7
  • Tidskriftsartikel (refereegranskat)abstract
    • The collection of residues from staple crop may contribute to meet EU regulations in renewable energy production without harming soil quality. At a global scale, chaff may have great potential to be used as a bioenergy source. However, chaff is not usually collected, and its loss can consist of up to one-fifth of the residual biomass harvestable. In the present work, a spreader able to manage the chaff (either spreading [SPR] on the soil aside to the straw swath or admixed [ADM] with the straw) at varying threshing conditions (with either 1 or 2 threshing rotors [1R and 2R, respectively] in the combine, which affects the mean length of the straw pieces). The fractions of the biomass available in field (grain, chaff, straw, and stubble) were measured, along with the performances of both grain harvesting and baling operations. Admixing chaff allowed for a slightly higher amount of straw fresh weight baled compared to SPR (+336 kg straw ha−1), but such result was not evident on a dry weight basis. At the one time, admixing chaff reduced the material capacity of the combine by 12.9%. Using 2R compared to 1R strongly reduced the length of the straw pieces, and increased the bale unit weight; however, it reduced the field efficiency of the grain harvesting operations by 11.9%. On average, the straw loss did not vary by the treatments applied and was 44% of the total residues available (computed excluding the stubble). In conclusion, admixing of chaff with straw is an option to increase the residues collected without compromising grain harvesting and straw baling efficiencies; in addition, it can reduce the energy needs for the bale logistics. According to the present data, improving the chaff collection can allow halving the loss of residues. However, further studies are needed to optimise both the chaff and the straw recoveries. © 2020 by the authors.
  • Engström, Jonas, et al. (författare)
  • Maskinnyckeltal för ett effektivare jordbruk
  • 2019
  • Rapport (övrigt vetenskapligt)abstract
    • I denna rapport presenteras ett av tre områden för att effektivisera jordbrukets logistik som undersökts i projektet ”Energieffektivisering av Jordbrukets logistik - fördjupning och utveckling” som har arbetat vidare på resultat från ett tidigare pilotprojekt om energieffektivisering av jordbrukets transporter. De tre områdena är, (1) skiftning av åkermark (2) planeringsverktyg för att simulera, planera och optimera logistikarbetet på gården (3) nyckeltal för logistikarbetet på gårdsnivå för att sporra till effektivisering. Alla tre bedöms som viktiga delar i arbetet med att effektivisera och minska energiåtgång och klimatpåverkan från jordbrukets transporter och i förlängningen livsmedelsproduktionen.I denna rapport har möjligheter att effektivisera maskinanvändningen på jordbruksföretag genom att använda kartläggning och nyckeltal undersökts. Detta har gjorts genom att maskinanvändning på tre gårdar loggats. Dessa gårdar var att betrakta som medelstora gårdar med svenska mått mätt och har olika produktionsinriktningar.Loggning genomfördes av dieselförbrukning och tidsåtgång för totalt nio maskiner på tre gårdar. Loggningsutrustningen kopplades till maskinernas CAN-bus och data laddades ner till Drivecs molntjänst via mobilt bredband. Loggning skedde också av GPS-data där maskinerna befann sig vid en viss tidpunkt och dessa refererades till olika skiften, inomgårdsområden, transportvägar och även t.ex. snöröjning eller annan entreprenadverksamhet.Ur dessa data beräknades nyckeltal manuellt fram för dieselförbrukning och tidsåtgång per gröda, fält och aktivitet. Nyckeltalen svarade mot vad lantbrukarna efterfrågade. För att vara rättvisande och heltäckande behöver loggningen vara mer tillförlitlig och inkludera alla maskiner i växtodlingen. En slutsats var att loggning och nyckeltalsberäkning måste ske helt automatiskt för att fylla en funktion och dessutom behöver nyckeltalet ha metadata som beskriver vad det beskriver, hur det samlats in och hur representativt det är.I projektet undersöktes också vilka möjligheter det fanns till att skicka denna information automatiskt från Drivecs system till LRF Konsults Digital Bonde och där integreras med ekonomiska data.Ytterligare forskning behövs för att nyttiggöra resultaten från detta projekt. Det behövs också målinriktat arbete med både vidareutveckling och kunskapsspridning till jordbrukare.
  • Lund, Johanna, et al. (författare)
  • Outnyttjat ensilage till förnybar energi
  • 2018
  • Rapport (övrigt vetenskapligt)abstract
    • There are large amounts of unutilized silage from agriculture and from municipalities that harvest meadows and grasslands. This biomass is a disposal problem and a cost. At the same time, there are biogas plants which have an increased demand for substrates that do not compete with the production of feed and food. Unutilized silage can be an excellent biogas substrate provided it is effectively pretreated. This study is conducted as a case study of Jordberga Biogas plant in Skåne (in the south of Sweden), although the results of the project are applicable to other regions in Sweden where unutilized silage exists. The project aim was to study a 20 % replacementof today’s crop-based substrates in Jordberga biogas plant with unutilized silage from agriculture and municipalities. The project has been conducted by RISE Agrifood and Bioscience in collaboration with the German Biomass Research Center (Deutsches Biomasseforschungszentrum, DBFZ), Gasum, County Administrative Board of Skåne and Fogda Farm.The project was divided into three parts. In the first part the amounts of different types of unutilized silage was estimated, from arable land and forage areas at municipalities and County Administrative Boards, for the area around the Gasum Biogas plant in Jordberga, and for Sweden in total. In a second part the adequate technique for pretreatment was identified and tested in practical trials on different types of unutilized silage. In the third part cost calculations were done for the disintegration of the unutilized silage.The study showed that the largest potential for unutilized silage is from forage production. The area of meadows is much less with much lower yield. An assumption was made that 5% of the total amount of unutilized silage bales are available for biogas production. Project calculations showed that 35% of these must be used to substitute 20% of the crop based substrates at Jordberga. Depending on the quality and biogas yield, 12-23 ton DM is needed per day.Based on earlier studies and experiences from the project group, three machines were chosen for the practical tests to disintegrate silage bales; Rot Grind, RS CutMaster and I-GRIND. Roto Grind and I-GRIND used hammermill technique whereas RS CutMasterused knife rotors for disintegration. All three machines managed to disintegrate silage bales with DM-content varying from 40-70% DM. The particle length after disintegration was analyzed and a visual estimation of the effect on particle structure was made. Particle size after disintegration was the same for Roto Grind and RS CutMaster whereas it was considerable longer for I-GRIND. Disintegration worked better on silage with lower DM content regarding both particle size and structure for all tested machines.Based on the test results RS CutMaster had higher total disintegration costs compared with Roto Grind and I-GRIND. The differences in costs was mainly due to lower measured capacity of RS CutMaster, and higher depreciation and maintenance costs of both RS CutMaster and I-GRIND. To lower the costs to same level as Roto Grind and I-GRIND, RS CutMaster would need approximately 40% higher capacity than measured in the tests.
  • Lund, Johanna, et al. (författare)
  • Unutilized Silage as a Biogas Substrate
  • 2018
  • Konferensbidrag (refereegranskat)abstract
    • Large amounts of unutilized silage are available in agriculture as well as from municipalities harvesting meadows and grasslands.At the same time, biogas plants with crop-based substrates are looking for alternative substrates to adapt to EU RED and toincrease profitability. Unutilized silage that would not otherwise be used for feed can be an excellent biogas substrate, but thematerial is often coarse and pretreatment is necessary. This project was performed as a case study to substitute 20% of the cropbasedsubstrate used today (maize, whole-crop silage and grain) with unutilized silage bales for the Jordberga biogas plant inthe south of Sweden.Three different mobile machines for disintegration of silage bales were used in practical trials to evaluate which was most effectiveat reducing particle length and damaging the structure of the grass for improved digestion. Two of the machines used ahammermill technique for disintegration and the third used knife rotors. Test results were evaluated regarding particle length,particle structure, energy consumption and capacity. Costs were calculated for the handling system of the bales from the farm orstorage site to the processing unit for disintegration and then to the digester.All three machines managed, to different extent, to reduce particle length and damage the structure of the grass. For a goodestimation of the capacity and fuel consumption further tests are needed. The purchase of bales and transport to the plant arethe largest costs in the system. It is therefore crucial for the interest of the biogas plants to use bales if they can have themdelivered for free at the gate. If and how much the biogas plant is prepared to pay for the bales is also highly dependent on howthe silage quality affects the methane yield potential.
  • Pari, Luigi, et al. (författare)
  • Combined harvesting of chaff and straw for bioethanol production : The first experience on wheat in Sweden
  • 2018
  • Ingår i: European Biomass Conf. Exhib. Proc.. ; , s. 289-293
  • Konferensbidrag (refereegranskat)abstract
    • The purpose of this work is the evaluation of a harvest chain aimed at incorporating the chaff into the straw bales as consequence of wheat harvest operation. The test was performed in August 2017 in Uppsala, Sweden, using a commercial hybrid combine harvester equipped with a modified chaff spreader and a tractor with round baler. In particular, the chaff spreader was used as chaff recovery system to redirect the chaff into the straw flow during its fall on the ground and get the product admixed in the straw swath. The combine was also used with the recovery systems in “spreading mode” to be experimented as control. A few companies are approaching this engineering challenge, however, as the market of agricultural residues for fuel production is growing, simple and affordable solutions should be identified and commercialized. This paper can be considered as a primary attempt to find a simplified and affordable solution in this direction. The results show different harvesting performances according to machine settings. Indeed, when the recovery system was used, the material falling into the swath and baled was about 340 kg (14%) higher per ha (dry basis). However, respect the amount of biomass potentially available for baling, high harvest losses were identified and indicated the need to repeat the test with other machineries and find further adjustments.
  • Gunnarsson, Carina, et al. (författare)
  • Fresh and ensiled crops - A new way to organize year-round substrate supply for a biogasplant : Report from a project within the collaborative research program Renewable transportationfuels and systems
  • 2017
  • Rapport (övrigt vetenskapligt)abstract
    • For crop-based biogas plants, the cost for buying the crops is a predominant production cost andefficient systems for production, harvesting, transportation and storage are therefore of major importance.Furthermore, there is a discussion going on about competition on land between food andenergy production. EU has decided to strongly limit the production of transportation fuel based oncrops grown on arable land. For crop-based biogas production it is therefore very interesting to examineways to reduce substrate costs for crops as well as to find alternative crops that are not competingwith food production.This project was carried out as a case study for two crop based biogas plants in Jordberga andÖrebro, both of them owned by Gasum AB, former Swedish Biogas International (SBI). The overallaim of the project was to reduce substrate costs by at least 10%, by organizing the supply ofcrops in a new way, combining fresh and ensiled crops. The underlying assumption was that substratecosts could be reduced by feeding fresh crops into the biogas digester during the harvest periodand thereby reduce costs for storage and avoid losses of dry matter during storage.The goal of this project was to improve cost calculations and develop an optimization model forsubstrate supply to analyze how different fresh and ensiled substrates should be best combined tominimize substrate costs during various times of the year. In the previous f3 financed project ”Optimizedlogistics for biogas production” a model based on linear programming was developed for optimizationand strategic planning of the logistics for biogas plants. In the present project, the modelwas further developed to optimize the supply for the year divided into different periods, instead ofon annual basis as in the previous project.[...]
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